Hybrid vehicles, plug-in and purely electrical vehicles, fuel-cell vehicles, and battery charging systems generally use voltages above 60 V. Statutory requirements often mandate that, when the rechargeable storage systems on battery-powered vehicles can overheat due to over-current, said vehicles must be equipped with safety devices such as fuses, circuit breakers, or master contactors that reliably disconnect the energy storage from the high-voltage electrical circuit if over-current occurs, regardless of the current direction. Corresponding contactors are well-known in the art. Such a contactor consists of two electrical contacts closed and/or connected by a movable switching element. The movable switching element is, for instance, moved between an idle position and a switched position by means of a coil and an anchor guided in the coil. One problem with contactors are contacts that do not completely open. This can, for instance, result in a single pole stuck contactor. While in this case the two contacts are electrically interrupted, the movable anchor is nevertheless unable to travel back to its idle position because one side of the switching element is stuck to the contact.
The German patent 102015224658.2 filed by the registrant describes an electro-mechanical circuit breaker with two contact pairs, wherein one contact of each of the contact pairs is physically segregated on a contact bridge. The circuit breaker also features an anchor connected with the contact bridge and movable along a range of motion. A micro-switch is also arranged in the proximity of the anchor or the contact bridge. This micro-switch is spaced to the anchor and/or the contact bridge such that the micro-switch is actuated when the anchor and/or the contact bridge is lowered by the range of motion. A defect can be identified with the micro-switch additionally arranged in the circuit breaker. The micro-switch is only actuated when the anchor has moved by the arranged range of motion, thus causing the circuit breaker to switch fault-free.
WO 2008/064694 A1 describes a method for detecting the ability of an electrical relay to function, along with a device to execute the method.
A switching arrangement and a method for monitoring an electro-magnetic relay is known from WO 2013/189527 A1.
US 2014/0002093 A1 describes a method for a relay contact monitor and control.